Cancer is the second leading cause of death and will directly affect approximately 40% of the people in the United States over the course of their life. Chemotherapy has been shown to be an effective therapeutic strategy, but it lacks specificity, resulting in a multitude of negative side effects. Targeted therapies such as Herceptin, Iressa, and Nivolumab have shown increased effectiveness against cancer by attacking specific molecules in the target cell. For example, Herceptin inhibits the HER2 protein, which is overproduced in some breast cancer cells, and stops cell division. Biotin is an innate coenzyme for carbohydrate, lipid and protein metabolism. Certain cancer types overexpress biotin transporters on the surface of each cancer cell in order to increase biotin absorption necessary for metabolic processes. Furthermore, the intracellular environment in cancer cells is more reducing compared to non-cancer cells due to increased metabolism. Ferrocene is an iron-based organometallic molecule that has been shown to generate reactive oxygen species (ROS) in the reducing environment of cancer cells. Given that certain cancer cells absorb biotin with a higher efficiency, we hypothesize that linking biotin to ferrocene will increase the efficiency of ferrocene entering the cell and result in selective cancer cell death. Therefore, we have produced a library of biotin-ferrocene conjugates to selectively target cancer cell lines that over express biotin receptor sites. Experiments were conducted utilizing ferrocene and a variety of ferrocene-biotin conjugates (C1, C2, 2) in both cancer (MCF-7) and noncancer (HEK 293) cell lines in order to compare the relative toxicity between compounds.

The Texas horned lizard (Phrynosoma cornutum) has always been believed to be an ant specialist, especially on harvester ants. However, a population of horned lizards in south Texas seem to have a more diverse diet consisting of other insects and arachnids. The goal of this project is to build a DNA library of order Coleoptera (beetles) that are preyed upon by these horned lizards. This DNA library will be compared to DNA extracted from horned lizard scat so that we can identify which species of beetles these lizards are eating. For this process, I isolated DNA from 244 beetles collected in pit fall traps from Kenedy and Karnes City, amplified the cytochrome oxidase I (COI) gene, and sequenced it. I compared the processed sequences to those available on GenBank and BOLD (Barcode of Life Database) to identify the species of beetle.

Oxidative stress in the brain is a known contributor to the development of neurodegenerative diseases, including Alzheimer’s. The focus of this project is to target the amyloid-β plaque formations and reactive oxygen species (ROS) derived from mis-regulated metal-ions that lead to disease-causing oxidative stress. The present investigation measures both the antioxidant reactivity and metal chelating ability of 1,4,11,13-tetra-aza-bis(2,6-pyridinophane)-8,17-ol (L4).  L4 contains two radical scavenging pyridol groups along with a metal-binding nitrogen rich ligand system.  It was hypothesized that increasing the number of pyridol groups on the ligands in our small molecule library would increase the radical scavenging activity, which in turn may provide cells protection from oxidative stress.  The radical scavenging ability of L4 was quantified using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical assay. This was compared to other radical scavenging small molecules to evaluate the effect of the additional radical scavenging group on the antioxidant activity.  The interaction of L4 with redox active metal-ions such as copper(II) was also evaluated using the coumarin-3-carboxylic acid (CCA) assay to show the molecule’s ability to target mis-regulated metal-ions in diseased tissues. With the end goal being to develop a potential biological therapeutic agent, metabolic stability studies were also performed.

Non-conventional solvents, such as room-temperature ionic liquids and deep-eutectic solvents, have attracted a lot of attention in recent years due their diverse applications in various areas of sciences, medicine and engineering. The ability to control physical properties of these solvents by simply adjusting their structure and/or the ratio of the components favorably distinguishes ionic and eutectic solvents from traditionally used molecular solvents as it allows to custom design specific types of media for given applications.

This presentation will highlight our efforts on various aspects of the synthesis of ionic liquids and deep-eutectic solvents as well as it will describe our investigations on the physical properties and nanostructural organization of these liquids using environmental probes, such as those that feature BODIPY and aza-BODIPY motifs. In addition, our initial studies on the design of multiphase systems that utilize ionic, eutectic and molecular solvents will be presented.

This project is aimed to modify a leucyl-tRNA synthetase (LeuRS) to incorporate fluorescent amino acids into proteins to produce fluorescent proteins in living cells. Fluorescent proteins are useful because they are easily analyzed and tracked in living organisms. In a small scale, we successfully prepared the library of LeuRS variants in which five amino acids are randomized in the leucine-binding site of a functional LeuRS without its editing domain. Currently, we are working on a large scale production of viable bacterial cells that cover the whole diversity of library (at least 34 million different LeuRS molecules). Initially, we attempted two-step process in which an N-terminal library fragment (for two randomized amino acids) is generated first and a C-terminal fragment (for three randomized amino acids) is added later. However, this two-step cloning process did not produce enough viable cells to cover all the possible variants. In a new approach, a complete library of LeuRS will be produced by overlapping extension PCR and introduced to E. coli in a single step to ensure highest possible transformation efficiency. Consequently, the library of LeuRS variants will be subject to a genetic selection experiment to obtain LeuRS variants that incorporate only fluorescent amino acids into proteins.